In his later writings, however, he expresses doubt as to the existence of such a substance, and we may omit further notice of it, especially since, if it really do occur, its properties are not distinct from those of Humic acid.
"Peat and its Uses as Fertilizer and Fuel"
Samuel William Johnson
A small portion of nitrogen unites with hydrogen, forming ammonia, which remains combined with the Humic and other acids.
"Peat and its Uses as Fertilizer and Fuel"
Samuel William Johnson
Mr. Staring, in his valuable memoir on the "Geological Map of Holland," has attributed the general scarcity of human bones in Dutch peat, notwithstanding the many works of art preserved in it, to the power of the Humic and sulphuric acids to dissolve bones, the peat in question being plentifully impregnated with such acids.
"The Antiquity of Man"
Charles Lyell